In untrained men performing cable curls with the same resistance, movement range, and effort, changing the shoulder angle between neutral and fully extended positions leads to similar increases in...
Mechanism
Synthesis from 1 study
When you curl with your arm in different shoulder positions but lift the same weight the same way, your biceps get the same workout every time — so they grow the same amount. It’s not where your shoulder is, it’s how hard your arm muscles have to work that matters.
Most probable mechanism
When you curl a weight with your arm in different shoulder positions but keep the same resistance and effort, the muscles on the front of your upper arm stretch and contract the same amount, so they experience the same level of stress and grow the same way.
The resistance profile and elbow range of motion are held constant, resulting in identical torque demands on the elbow flexor muscles during concentric and eccentric phases.
Muscle fiber recruitment patterns and force production in the biceps brachii and brachialis remain consistent across shoulder positions due to matched external load and perceived exertion.
Mechanical tension applied to the muscle-tendon units of the elbow flexors is equivalent in both shoulder positions, leading to similar activation of intracellular signaling pathways that trigger protein synthesis.
The cumulative mechanical stimulus over the training period results in comparable rates of myofibrillar protein accretion and muscle fiber enlargement at both proximal and distal regions of the elbow flexors.
Evidence from Studies
Supporting (1)
Community contributions welcome
The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.